Frequency Synthesiser / Multiple LO Source

Transcription

1 Three LO sources in one single 6U VME package ideal for Multi-stage dual/treble down-converter Application. The is a multiple LO module used to generate three pairs of LO signals, each pair being phase matched in order to provide the capability drive two phase and amplitude matched, high sensitivity narrowband receivers such as required for EW receiver system with DF functionality. The following block diagram depicts the basic architecture of the RA62. The Stepped Frequency Synthesiser is based upon Direct Frequency Synthesis, DFS, technique, whereby the 1GHz input reference signals is multiplied, filtered and mixed accordingly to generate simultaneously a given number of isolated and filtered single tone CW signals from the 1GHz comb. A finely tuned signal is then generated using a multiway switch to select between the 1GHz spaced CW tones and mixed with fine resolution signals generated using a bespoke DDS/VCO PLL network. In this way finely tuned signals can be generated between 7.5GHz and 23GHz. This signal is present at ports J1 and J2. The 1GHz comb tones are also available as fixed CW frequency signals at ports J3 and J4. These tones are independently selected to the finetuned signal. The 4 GHz fixed signal at the J5 and J6 outputs and the internally generated internal reference signals are generated using a VCO that is phase locked to the same externally or internally generated 100MHz reference signal as the other outputs. In the absence of the external reference signal, a high performance internally generated reference is automatically selected. A number of signals are generated, including supply voltage monitoring, PLL lock-detect, LO output power level threshold signal, temperature and runtime indication. APPLICATIONS Military narrowband EW Receivers DF Receiver systems Test LO sources FEATURES Three separate LO outputs designed to drive mixers in three stage RF converters. o LO1. Fixed single tone CW frequency output with frequency selectable from three frequencies 10, 12 and 14 GHz. o LO2. Stepped LO output tuneable from 7.5GHz to 23GHz 1kHz step size as standard, 1Hz option. o LO3. Fixed 4GHz CW output as standard. Other frequencies available at low cost NRE. Matched Dual LO Outputs capable of driving matched receiver/converter systems. Tuning speed 200µs for standard product. Faster switching speed can be accommodated for customised versions. Very low phase noise (subject to reference source) Integrated Internal References as failsafe back-up that automatically switch in when external reference is lost Very low spurious signal level High RF power at all ports capable of driving converter mixer directly E VME, SPI, UART Interfaces (customer specific control interface can be accommodated) Page 1 of 7

2 SCHEMATIC PORT DEFINITION J1, J2 Tuned output signal or disabled. A minimum of 80dB isolation is provided when disabled. J3, J4 Provides one of three signals (10GHz, 12GHz or 14GHz). Alternatively, the stepped output signal can be available at these parts (ports J1 and J2. Minimum isolation between non-selected signals is 80dB (all can be disabled). NOTE: the stepped output signal is only available at this port when J1 and J2 are disabled J5, J6 4.00GHz fixed output only (note: this can be disabled with a minimum of 30dB isolation Page 2 of 7

3 MODES OF OPERATION Port J1 & J2 Ports J3 & J4 Ports J5 and J6 Mode 1 Tuned Output Switched CW output 4 GHz Mode 2 Tuned Output High isolation 4 GHz Mode 3 High Isolation Tuned Output 4 GHz Mode 4 High Isolation High Isolation High Isolation SPECIFICATIONS J7 1GHz Reference Input Input Power Level 7dBm +/- 2dB Impedance 50Ω Accuracy of reference signal used to measure the output frequency accuracy at ports J1 to J4. SSB Phase Noise External 1GHz reference signal level valid Bit Phase Noise of the input 1GHz reference signal used to measure the output frequency phase noise at ports J1 to J4. J8 100MHz Reference Input Port Input Power Level 7dBm +/- 2dB Impedance 50Ω Accuracy of reference signal used to measure the output frequency accuracy at ports J5 & J6. SSB Phase Noise External 100MHz Reference signal level valid bit Phase Noise of reference signal used to measure the output frequency phase noise at ports J5 & J Page 3 of 7

4 J1 & J2 Tuned Frequency Output Ports Output frequency Range 7.5 to 23.0 GHz Frequency Step Size 1kHz Optional 1.0 Hz step size Output Power +/- 1.0 PPM 17dBm +/- 2dB Directly dependent on the reference signal accuracy SSB Phase noise Phase noise dependent on the phase noise of the 1GHz reference input. Non-Harmonic Spurious Signals Level -65dBc Maximum Measured in band DC-24 GHz Harmonic Signal Level -20dBc Isolation 80dB minimum Once both J1 and J2 port are disabled Switching Speed 200µs Out Power Valid bit & DDS/PLL lock detect bit Output frequency Range Output Switched to single tone Mode A single CW tone Selected from 10GHz, 12GHz or 14GHz. Output Frequency Range 7.5GHz to 23GHz in steps of Output switched to tuned 1kHz. frequency mode Output Power 17dBm +/- 2dB Time between 50% input command signal level to within 1dB steady state RF output level at new required frequency. See Note 1 below. J3 & J4 - Switched Frequency Output Specification Note: J3 and J4 can be alternated between discrete and tuned Frequency output under user command. In the mode where a tuned output is selected, the output signal specification is as that of ports J1 to J2 specification listed above. The tuned output specification is similar to that specified above for the J1 and J2 output ports. Directly dependent on the reference signal accuracy SSB Phase noise (14GHz Tone) Non-Harmonic Spurious Signals Level Harmonic Signal Level Isolation between selected and deselected tones. Isolation between Switched and Stepped signals dBc Maximum -20dBc 80dB minimum 80dB minimum Output Power level Valid bit plus DDS/PLL lock detected when ports J3 and J4 switched to tuned frequency output. Phase noise at all offsets is dependent on the phase noise of the 1GHz reference input. Results shown are obtained with a reference as defined for J8 above. Measured in band DC-24 GHz When Ports J3 and J4 are disabled Page 4 of 7

5 J5 & J6 - Fixed 4GHz Output. Note: As a standard Port J5 and J6 output frequency is fixed at 4GHz. Other fixed frequencies between 2.0 and 4.5GHz are optional. Output frequency. 4GHz CW. See note above. Output Power 18dBm +/- 2dB SSB Phase noise Phase noise at 1MHz offset is dependent on the phase noise of the 100MHz reference input. Results shown are obtained with a reference as defined for J8 above. Non-Harmonic Spurious Signals Level -65dBc Maximum Measured in band DC-24 GHz Harmonic Signal Level -20dBc Isolation 30dB When J5 and J6 are disabled J5 and J6 output power level Valid and Lock detect Bit. Connector, Control and DC power Supplies Note: All DC supplies provided through VME back plane connector DC power Supplies Control -12V ± 300mA maximum +5V ± 3000mA maximum +12V ± 750mA maximum The following control interfaces are offered as standard: 1. Geographically Addressed VME Slave Control using VME Standard Backplane a) Direct Tuning via VME Address Space b) VME Addressed Frequency Step Table, incremented via realtime differential LVTTL input. 2. SPI interface LVTTL 1 3. Serial UART 1 a) Single Ended LVTTL b) Differential LVTTL Supplied through standard VME back plane connector power supply PINs 1 Via VME user defined pins on VME P2 backplane connector. RF Connectors Ports J1 to J8 Supply and Control Connectors SMA Female 160 Pin Male, IEC Performance Levels According to DIN Front Panel Connectors 2 back plane connectors Page 5 of 7

6 ENVIRONMENTAL SPECIFICATIONS Operating Temperature Storage Temperature -20 o C to +85 o C RTCA-DO-160C sec 4 Cat A1-54 o C to +125 o C Altitude ft (4600m) RTCA-DO-160C sec 4 Cat A1 Humidity 85% RTCA-DO-160C sec 6 Cat A Vibration 6.0g rms RTCA-DO-160C Fig 8-1 Cat B CE03, CE-04 See note in Appendix E MIL-STD-461C EMC CS-01, CS-02 See note in Appendix E MIL-STD-461C Optional -40 o C to +85 o C Including both Electromagnetic Capability and Susceptibility Page 6 of 7

7 MECHANICAL OUTLINE The synthesiser is packaged in a 6U 4HP VME compatible format Page 7 of 7